Question

Find the 7th partial sum of (infinit) over E and under E is i=1, then the equation on the right side of E is 6(3)^(i-1).

*the E is the sigma notation symbol*
please help

Answer 1

since i=1,
6(3)^i-1
6(3)^1-1
6(3)^0
6(1)
=6.
:- 6(3)^i-1 = 6

Answer 2

The partial sum can be determined through the calculator or substituting the value to the variable manually.

6(3)^(1-1) = 6
6(3)^(2-1) = 18
6(3)^(3-1) = 54
6(3)^(4-1) = 162
6(3)^(5-1) = 486
6(3)^(6-1) = 1458
6(3)^(7-1) = 4374

total is 6558